Chemical and Biological Engineering

Influence of Confinement and Interfacial Interactions on the Behavior of Membranes and Materials for Energy Technologies

The rapid growth of energy-centric research efforts have stemmed from the clear and present need to improve energy efficiency, reduce greenhouse gas emissions, and to define alternative, renewable energy sources.  Membrane materials offer potential solutions to many of these issues.  Membrane-based separations provide a low-energy alternative to large-scale, energy intensive industrial separation processes and offer competitive opportunities for carbon capture compared to traditional scrubbing technologies.  Additionally, membranes are an integral component of energy storage and delivery technologies such as batteries and fuel cells. 

In order to maximize the productivity of membrane materials, they are typically designed to possess structures with nano-scale dimensions.  In separation membranes, for example, the ‘active’ separating layer is typically on the order of 100 nm thick.  These confined, ultrathin films enable the high productivity required for commercially viability.  An additional benefit of utilizing thin-film technologies is that the amount of high value, high-performance material required in the production of multi-component membranes is minimized.  However, identifying how materials will perform in confined systems is complicated because significant deviations from bulk behavior may occur in nanostructured materials.  Predicting and understanding the physical performance and behavior of these confined, nano-structured membranes are further complicated because the materials required for separations and energy technologies are typically highly non-equilibrium materials whose properties can change dramatically with time. 

There is currently a large gap in the fundamental understanding of how confinement and interfacial interactions influence performance and subsequent material stability over the timescales of practical applications.  If these factors were better understood, strategies to manipulate membrane structure and interfacial interactions could be developed to further improve membrane material performance.  Furthermore, the development of realistic accelerated aging tests and long-term predictive models will be required to prove the long term viability of these technologies.  This seminar will present an overview of research aimed at understanding the accelerated aging behavior of ultrathin films used in gas separation membranes and the influence of confinement and interfacial interactions on the performance of polymer electrolyte membrane (PEM) materials.